The PROSITE dictionary of sites and patterns in proteins, its current status

PROSITE is a compilation of sites and patterns found in protein sequences; it can be used as a method of determining the function of uncharacterized proteins translated from genomic or cDNA sequences. In some cases the sequence of an unknown protein is too distantly related to any protein of known structure to detect its resemblance by overall sequence alignment, but relationships can be revealed by the occurrence in its sequence of a particular cluster of residue types which is variously known as a pattern, motif, signature, or fingerprint. These motifs arise because specific region(s) of a protein which may be important, for example, for their binding properties or for their enzymatic activity are conserved in both structure and sequence. These structural requirements impose very tight constraints on the evolution of these small but important portion(s) of a protein sequence. The use of protein sequence patterns to determine the function of proteins is becoming very rapidly one of the essential tools of sequence analysis. This reality has been recognized by many authors [1,2]. While there have been a number of reviews of published patterns [3,4,5], no attempt had been made until very recently [6,7] to systematically collect biologically significant patterns or to discover new ones. Based on these observations, we decided in 1988, to actively pursue the development of a database of patterns which would be used to search against sequences of unknown function. This database, called PROSITE, contains some patterns which have been published in the literature, but the majority have been developed in the last four years by the author.